|Image from Bright Days.|
One of the basic components of mulch gardening is to allow organic compounds to fertilize your vegetation. Leaves, small twigs, compost, and other materials decompose and give nutrients to your soil; thereby allowing for healthier, more dynamic crops. But of course, the same is true for your lawn! Grass loves healthy soil—but many homeowners wrongly think clearing the ground, raking, and otherwise sanitizing the lawn is the best thing. That line of thought creates the heady chemical concoction of spray fertilizers and other pesticides that wreaks havoc on living systems and actually in the long term can cause a lot of damage to a lawn and everything living in it.
People understandably want their lawns to be beautiful. So we're not suggesting dumping compost on your grass year-round (though leaves, twigs, and regular compost can be added to your garden beds year-round); but we are suggesting that your late-season leaves be mowed into your lawn instead of getting swept away.
From Fine Gardening:
Based upon research at several universities, the organic matter and nutrients from leaves mown into lawn areas has been proven to improve turf quality. At Michigan State, researchers set a rotary mower to cut at a height of 3 inches and then mowed an 18-inch-deep layer of leaves into test plots. That’s the equivalent of 450 pounds of leaves per 1,000 square feet. The tests resulted in improved soil and healthy lawns with few remnant leaves visible the following spring.
You can achieve similar results if you set your mower to cut at the same height as in the Michigan State study, and mow at least once a week during peak leaf fall when your lawn reaches a height of 4 inches. Leaves shred most efficiently when slightly damp, so mow after a light dew. If you follow these simple guidelines, you will never rake another leaf and improve the quality of your soil.
To treat leaves as trash is both environmentally foolish and financially ruinous. Currently, many municipalities encourage residents to rake leaves to the curb for collection, but before they are collected, heavy rains often wash the leaves into catch basins. There, they decompose and release phosphorus and nitrogen into streams and rivers that flow through the community. These excess nutrients contribute to algae blooms during the summer, which result in lower oxygen levels, making it difficult for fish and other aquatic species to survive.
Municipalities, both large and small, spend thousands, even millions, of dollars each year to collect, transport, and process autumn leaves, tying up resources that could be used elsewhere in our communities. If we all keep our leaves on our properties, we will improve our gardens, save money, and enhance the environment we all share.